Dive Lab Xlds Rdc 3 And Interspiro Dp2 As Candidates For An Extreme Lightweight Diving System Unmanned

INTRODUCTION: Commercial lightweight surface Supply divers' consoles underwent unmanned resistive effort testing. This report presents results from the Dive Lab XLDS RDC-3 and Interspiro DP2 lightweight consoles. METHODS: Four Dive Lab XLDS RDC-3 and five Interspiro DP2 consoles were tested. Resistive effort wee determined at a water temperature of 38 F (3.3 C). A breathing simulator with a sine wave breathing pattern was used, and the exhaled air was heated and humidified. Testing was done at depths from the surface to 198 feet of seawater (fsw; 60.7 meters of seawater [msw]) in steps of 33 fsw (10.1 msw) and at ventilations ranging from 22.5 L/min to 90 L/min. RESULTS: The Dive Lab XLDS RDC-3 console met the NEDU resistive effort performance goal of 1.75 kPa at a respiratory minute volume (RMV) of 62.5 L/min to 132 fsw with the MK 20 (nonpositive pressure) full face mask and to 165 fsw with the MK 21 helmet. The Interspiro DP2 console met this same performance goal to 198 fsw with the Divator MKII (positive pressure) full face mask.

The Interspiro DP2 and Divator MK II UBAs with the Divator positive-pressure and nonpositive-pressure full face masks (FFMs) were evaluated as possible candidate UBAs for inclusion on the Authorised for Navy Use (ANU) List. Resistive effort (RE) evaluations were conducted in 38 F fresh water and 29 F salt water. A free-flow evaluation - in which one FFM was breathed with a Reimers breathing simulator while a second FFM was allowed to free flow to determine whether it would degrade the RE of a second diver's FFM - was conducted for the DP2. With 1500 and 500 psig breathing gas supply pressures, the Divator MK II scuba met the Navy Experimental Diving Unit (NEDU) RE goal of 1.37 kPa at 62.5 L/min for Category 1 UBAs to a depth of 132 fsw with both the positive-pressure and nonpositive-pressure FFMs. With a 1500 psig breathing gas supply pressure, the DP2 met the NEDU goal of 1.76 kPa at 62.5 L/min for Category 2 UBAs to a depth of 198 fsw in 38 F water with the positive-pressure and nonpositive-pressure FFMs. At 29 F this goal was met to 198 fsw with the nonpositive-pressure FFM and to 165 fsw with the positive-pressure FFM.